Valve housing assemblies often have a valve body member with a cap threaded thereon. The cap member is needed to retain the valve mechanism within the cavity of the valve housing. The cap member once installed needs to occasionally be removed for access to the valve mechanism for maintenance and repair. The cap is also constructed with an abutment shoulder to abut a complementary shoulder in the valve body member to provide a stop to prevent overtightening and overcompression of the valve mechanism.
Many cap members have been designed so that they only need to be hand tightened. Adjustment rings threadably engage an inner rim of the cap member to properly seat the valve elements. However, people try to tighten the cap and not use the adjustment ring in spite of the fact that written instructions call for using the adjustment ring. Unnecessary efforts are often made to even further tighten the cap onto the valve body member after the adjustment shoulder abuts the complementary shoulder. Such efforts overtighten the cap member onto the body member and can cause difficulties in removal of the cap. Proper removal of the cap calls for loosening of the adjustment ring. However, written instructions calling for the loosening of the adjustment ring are also sometimes ignored and the cap is often loosened without first loosening the adjustment ring.
The force needed to loosen the cap can be further aggravated due to corrosive action of water that may drip into the threaded section of the cap and valve housing member over long periods of time.
What is needed is an abutment mechanism which provides for a fixed stop between the cap member and valve body member but has a release mechanism which reduces the locking force needlessly exerted by some people so that when the cap needs to be removed it can be easily removed in spite of the fact that the cap was overtightened or the adjustment ring was not first loosened.